The present invention relates to a mass production system for synthesized carbon nanotubes, and a mass production method thereof using the same. More particularly, the present invention relates to a mass production system for synthesized carbon nanotubes using a vapor synthesis method, and a mass production method thereof using the same.
The carbon nanotubes are composed of graphite sheets wound in a cylindrical shape, and can be classified into single-wall carbon nanotubes, double-wall carbon nanotubes, and multi-wall carbon nanotubes according to the number of graphite sheets.
Carbon nanotubes are anticipated to be useful in a wide variety of applications, for example, electronic information industry, energy industry, high performance composite materials, ultra-fine nano components, etc., in view of their light weight, excellent electrical and mechanical properties, chemical stability, and easy surface reaction. Accordingly, it is necessary to provide a method for synthesizing highly pure carbon nanotubes at low costs in mass production.
Currently, representative methods for synthesizing the carbon nanotubes include an arc-discharge method, a laser deposition method, a chemical vapor deposition method, and a vapor synthesis method. For the arc-discharge method or the laser deposition method, since amorphous materials are generated along with the carbon nanotubes when synthesizing the carbon nanotubes, it is necessary to perform a thermal or chemical refinement process in order to obtain highly pure carbon nanotubes, and it is difficult to accomplish economical mass production. For the chemical vapor deposition method, although it is possible to synthesize highly pure carbon nanotubes by aligning them on a substrate, it is also difficult to accomplish their mass production.
Meanwhile, the vapor synthesis method has been spotlighted as a method for synthesizing the carbon nanotubes at low costs. However, although various vapor synthesis methods have been developed, there is a problem in that the carbon nanotubes synthesized by the conventional vapor synthesis methods comprises a high quantity of amorphous carbon particles, making it difficult to refine the carbon nanotubes. Specifically, the vapor synthesis methods are considered inappropriate for mass production of, especially, the single-wall or double-wall carbon nanotubes in terms of their significantly low yield, and high quantity of amorphous carbon particles contained in the synthesized carbon nanotubes.
In addition, the mass production system of the carbon nanotubes employing the vapor synthesis process is a batch type system in which the carbon nanotubes are synthesized by repeating a series of steps of inputting a metal catalyst into a reaction chamber, heating the reaction chamber for a predetermined period of time, and then cooling the reaction chamber for every batch. However, such a mass production system has problems in terms of high manufacturing costs and significantly low productivity due to repetition of the individual steps as described above for every batch, and of low uniformity of the carbon nanotubes due to difficulty of obtaining the same process conditions for every batch.